Q. Someone vacationing cross country in a trailer, can he place his menorah by the window and keep travelling during the half hour, while it is lit?

A. Orchois Chaim (quoted by Beis Yosef O.H. 677), maintains that one sailing in a boat recites a brocho for ner Chanuka. Although, Rashi (Shabbos 23a) seems to say otherwise, Avnei Yashfa (O.H. 5: 94: 2) explains that the Orchois Chaim refers to someone travelling inside a boat’s cabin. Horav Tzi Pesach Frank zt”l (Mikroei Kodesh – Chanuka 18) also rules to light on a ship with a brocho. (See Igrois Moishe Y.D. 3: 14: 5 and next question).
Maharsham (4: 146) asserts that one should light Chanuka candles while travelling on a train, since there is no requirement for an established house (diras keva) as you do need for mezuza. Aruch Hashulchan (O.H. 677: 5) also maintains that you recite the brochos while the train is moving. Shearim Metzuyanim Behalacha (3: 139: 13) deduces from the above, that you are also obliged on ner Chanuka when travelling by plane. See questions 666 and 1212 on this forum as how to comply when flying. See also question 418 about kindling in a car.
Horav Shlomo Miller’s Shlit’a opinion is that one should light the menorah with a brocho when travelling in a camper. If possible, one should stop the vehicle for the half hour of compliance with the mitzva.

Rabbi A. Bartfeld as revised bt Horav Shlomo Miller Shlit’a